Hi,
I agree with alien scones for both of his number (1) as alerts, with the second being more important to me.
Vinz also brings up some good points on the trigger of events from site testing. A site owner settable note or flag could be a possible solution. The site could post a testing or station owner initiated shutdown. Being able to use a meta data flag to filter results could be useful.
Due to sparse coverage in some areas, a 500 km circle may not always work. As well locations normally downwind versus upwind from reactors should be considered.
I would love to be notified when any site changes by a set amount or goes offline as a minimum with set points added latter. A settable areas or other features could be added latter.
Now some user groups let the user select to be notified of each change, or allow daily email updates…..
I love an hourly text update of just stations that go up by a set value which I hope is not too often.